WO2024098326A1 - 波束扫描*** - Google Patents

波束扫描*** Download PDF

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Publication number
WO2024098326A1
WO2024098326A1 PCT/CN2022/131135 CN2022131135W WO2024098326A1 WO 2024098326 A1 WO2024098326 A1 WO 2024098326A1 CN 2022131135 W CN2022131135 W CN 2022131135W WO 2024098326 A1 WO2024098326 A1 WO 2024098326A1
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WO
WIPO (PCT)
Prior art keywords
antenna
plane
reference line
transmitting antennas
along
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PCT/CN2022/131135
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English (en)
French (fr)
Inventor
黄毅
龚龑
段侪杰
胡巍
林华杰
Original Assignee
深圳市华屹医疗科技有限公司
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Application filed by 深圳市华屹医疗科技有限公司 filed Critical 深圳市华屹医疗科技有限公司
Priority to PCT/CN2022/131135 priority Critical patent/WO2024098326A1/zh
Priority to US18/203,605 priority patent/US20240162966A1/en
Publication of WO2024098326A1 publication Critical patent/WO2024098326A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
    • H04B7/0695—Hybrid systems, i.e. switching and simultaneous transmission using beam selection
    • H04B7/06952—Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping

Definitions

  • the present specification relates to the field of wireless technology, and in particular to a beam scanning system.
  • the antenna module can realize beam scanning in a specified direction (or direction range).
  • Some application scenarios such as autonomous driving, medical imaging, etc.
  • electronic equipment such as radar
  • two-dimensional beam scanning capabilities so that the electronic equipment can generate images with higher resolution.
  • the related technology needs to arrange multiple antennas in at least two dimensions.
  • the beam scanning system arranges multiple antennas along a first direction, and realizes beam scanning in one spatial dimension through these antennas; the beam scanning system also arranges multiple antennas along a second direction, and realizes beam scanning in another spatial dimension through these antennas.
  • the above-mentioned related technology needs to set up a large number of antennas in the beam scanning system, and accordingly, it is also necessary to set up a separate transmit/receive channel (such as a low-noise amplifier, a mixer, an intermediate frequency filter, and an analog-to-digital converter/digital-to-analog converter, etc.) for each antenna to process the signal.
  • a separate transmit/receive channel such as a low-noise amplifier, a mixer, an intermediate frequency filter, and an analog-to-digital converter/digital-to-analog converter, etc.
  • This specification provides a beam scanning system that can realize beam scanning in two-dimensional space at low cost.
  • the present specification provides a beam scanning system, comprising: an antenna module and a signal processing circuit, wherein the antenna module comprises N transmitting antennas arranged along a first direction in a first plane, wherein N is an integer greater than 1, and each transmitting antenna extends along a second direction of the first plane, and is configured to convert an electrical signal into a millimeter-wave electromagnetic signal, wherein the N millimeter-wave electromagnetic signals emitted by the N transmitting antennas form a target beam; the signal processing circuit is connected to the antenna module, and when in operation, controls the target beam to perform two-dimensional scanning by outputting one frequency- and phase-controllable electrical signal to each of the N transmitting antennas.
  • the signal processing circuit controls the direction of the target beam to scan along the second plane by adjusting the frequencies of the N electrical signals to change within a preset frequency band.
  • the second plane is perpendicular to the first plane and parallel to the second direction.
  • each of the transmitting antennas corresponds to K radiation units along the second direction, and each of the radiation units converts part of the electrical signal into the millimeter wave electromagnetic signal, and K is an integer greater than 1; wherein, there is a first phase difference between the millimeter wave electromagnetic signals emitted by any two adjacent radiation units, and the first phase difference changes with the frequency of the electrical signal, so that the direction of the target beam scans along the second plane.
  • each of the transmitting antennas includes a long axis extending along the second direction, and there are correspondingly a first reference line and a second reference line on both sides of the long axis, the first reference line and the second reference line are respectively non-straight lines extending along the second direction; and both ends of each of the radiating units are respectively located on the first reference line and the second reference line.
  • the first reference line and the second reference line are respectively smooth curves, so that the energy loss of the transmitting antenna when working is less than a preset threshold.
  • both the first reference line and the second reference line are periodic target curves or target broken lines.
  • the first reference line and the second reference line are asymmetric along the long axis.
  • each of the transmitting antennas includes a first metal sheet on which K slots are sequentially arranged along the second direction; wherein, when the transmitting antenna is operating, the K slots partially leak the millimeter wave electromagnetic signal to form the K radiation units.
  • the edge of each of the slits is a smooth edge.
  • each of the transmitting antennas further includes: a substrate, a second metal sheet, and a plurality of metallized through holes; wherein the substrate includes a first surface and a second surface disposed opposite to each other, the first metal sheet is disposed on the first surface; the second metal sheet is disposed on the second surface and is configured to be grounded; each of the metallized through holes passes through the first metal sheet, the substrate, and the second metal sheet, and the plurality of metallized through holes surround the K gaps.
  • the signal processing circuit controls the direction of the target beam to scan along a third plane by adjusting the second phase difference between the N electrical signals.
  • the third plane is perpendicular to the first plane and parallel to the first direction.
  • the operating wavelength of the antenna module is ⁇
  • the distance between any two adjacent transmitting antennas in the antenna module is d1
  • the difference between d1 and ⁇ /2 is within a preset range.
  • the operating frequency band of the antenna module includes: 60GHz-64GHz.
  • the beam scanning system includes an antenna module and a signal processing circuit, wherein the antenna module includes N transmitting antennas arranged along a first direction in a first plane, N is an integer greater than 1, each transmitting antenna extends along a second direction of the first plane, and is configured to convert an electrical signal into a millimeter wave electromagnetic signal, and the N millimeter wave electromagnetic signals emitted by the N transmitting antennas form a target beam; the signal processing circuit is connected to the antenna module, and when working, it outputs a frequency and phase controllable electrical signal to the N transmitting antennas to control the target beam for two-dimensional scanning.
  • the present application solution can adjust the frequency and phase of the electrical signal output to the N transmitting antennas through the signal processing circuit when the antenna module arranges multiple transmitting antennas only in one direction (first direction), so as to realize the two-dimensional scanning of the target beam.
  • the number of transmitting antennas in the antenna module is reduced, and accordingly, the number of channels working with the transmitting antennas will also be reduced, thereby reducing costs.
  • the beam scanning system provided by the present application can realize two-dimensional scanning of the target beam at a low cost.
  • FIG1 shows a schematic diagram of a beam scanning system provided according to an embodiment of this specification
  • FIG2 is a schematic diagram showing the beam scanning system shown in FIG1 performing beam scanning
  • FIG3 shows a front view of a leaky wave antenna provided according to an embodiment of the present specification
  • FIG4 shows a side view of the leaky wave antenna shown in FIG3 ;
  • FIG5 shows an enlarged view of section A in FIG3 ;
  • FIG6 shows a rear view of the leaky wave antenna shown in FIG3 ;
  • FIG7 shows a radiation pattern of a beam scanning system in the yOz plane according to an embodiment of the present specification.
  • FIG. 8 shows a radiation pattern of a beam scanning system in the xOy plane according to an embodiment of the present specification.
  • Beamforming also known as beamforming or spatial filtering, is a signal processing technology that uses an antenna array to send and receive signals in a directional manner. Beamforming technology adjusts the parameters of the antenna units in the antenna array so that signals at certain angles interfere constructively and signals at other angles interfere destructively, ultimately forming a directional beam. Beamforming can be used for both signal transmitters and receivers.
  • Antenna pattern also called radiation pattern, refers to the graph of the relative field strength (normalized modulus) of the radiation field changing with direction at a certain distance from the antenna. It is usually represented by two mutually perpendicular plane patterns in the direction of maximum radiation of the antenna. Antenna patterns usually have two or more lobes, of which the lobe with the greatest radiation intensity is called the main lobe, and the remaining lobes are called secondary lobes or side lobes. The side lobes in the opposite direction of the main lobe are called back lobes.
  • the beam in this context, refers to the main lobe of the antenna pattern, which is the part where the antenna's radiation capability is most concentrated.
  • the shape of the beam can be arbitrary and is determined by the beamforming technology used by the antenna.
  • the direction of the beam refers to the direction in which the beam points, and may also be referred to as the emission direction of the beam, or the scanning direction of the beam.
  • the direction of the beam may specifically refer to the direction in which the central axis of the beam (i.e., the part with the most concentrated energy) points.
  • Millimeter waves electromagnetic waves with a wavelength of 1 to 10 mm (frequency range of 30 to 300 GHz) can be called millimeter waves. Millimeter waves are located in the wavelength range where microwaves and far-infrared waves overlap, and therefore have the characteristics of both spectra. Compared with infrared waves, millimeter waves have a narrow beam and can more accurately distinguish targets and restore the details of targets. Compared with lasers, millimeter waves are less affected by changes in weather and external environment (such as rain, snow, dust, sunlight, etc.) and have lower climate requirements. Compared with microwaves, millimeter wave components are smaller in size, and millimeter wave equipment is easier to miniaturize.
  • Leaky wave antenna when electromagnetic waves propagate along a traveling wave structure, if radiation is continuously generated along this structure, the radiated wave is called a leaky wave.
  • This structure that generates leaky waves is called a leaky wave antenna.
  • Leaky wave antenna is a traveling wave antenna.
  • a traveling wave antenna refers to an antenna whose fed electromagnetic field presents a traveling wave state distribution.
  • the leaky wave antenna also has the characteristic of beam scanning with frequency, that is, the direction of the beam changes with frequency.
  • Leaky wave antennas are usually formed by opening periodic gaps on the waveguide wall. When the leaky wave antenna is working, the electromagnetic wave signal transmitted inside the waveguide continuously leaks out from the periodic gaps on the waveguide wall to generate radiation, forming a highly directive, frequency-controllable beam scanning radiation pattern.
  • the scanning rate of a leaky wave antenna is used to characterize how quickly the scanning angle of the beam (main lobe) emitted by the leaky wave antenna changes with frequency.
  • the ratio between the change ⁇ in the scanning angle of the beam emitted by the leaky wave antenna and the frequency change ⁇ f may be used as the scanning rate of the leaky wave antenna.
  • the scanning rate of the leaky wave antenna is high, it means that the beam pointing of the leaky wave antenna is more sensitive to changes in frequency, that is, a smaller change in frequency can cause the beam to sweep over a larger angle. Therefore, the scanning rate of the leaky wave antenna can also be called the sensitivity of the leaky wave antenna to frequency changes.
  • Antenna array an antenna system consisting of two or more single antennas that are fed and arranged in space according to certain requirements is called an antenna array, or an antenna array.
  • the radiation field of an antenna array is the vector sum of the radiation fields of each single antenna, and its characteristics depend on the form, position, arrangement, excitation amplitude and phase of the single antenna.
  • End-fire direction and broadside direction if the maximum radiation direction of the antenna is parallel to the antenna, then the maximum radiation direction is the end-fire direction; if the maximum radiation direction of the antenna is perpendicular to the antenna, then the maximum radiation direction is the broadside direction.
  • millimeter wave radar has the characteristics of short wavelength and small equipment size, and has obvious advantages in detection accuracy and detection distance. Therefore, it plays a very important role in autonomous driving scenarios.
  • Millimeter wave radar is equipped with a transmitting antenna and a receiving antenna.
  • the transmitting antenna can transmit directional millimeter waves.
  • the receiving antenna receives the reflected echo.
  • the radar can determine the location of the obstacle based on factors such as the time when the transmitting antenna transmits the millimeter wave, the time when the receiving antenna receives the echo, and the driving speed of the vehicle.
  • the radar can also determine the speed, azimuth and other information of the obstacle based on the frequency, phase and other information of the millimeter wave emitted by the transmitting antenna, and the frequency, phase and other information of the echo received by the receiving antenna. It can be seen that millimeter wave radar can help vehicles accurately perceive the surrounding environment, quickly identify the distance, angle, speed and other information between surrounding obstacles and vehicles, and ensure the safe driving of the vehicle.
  • millimeter wave imaging The principle of millimeter wave imaging is to illuminate the object under test with millimeter waves, and then reconstruct the shape or dielectric constant distribution of the object under test based on the measured value of the external scattered field of the object under test. Since the size of the dielectric constant is closely related to the water content of biological tissue, millimeter wave imaging is very suitable for imaging biological tissue. Therefore, millimeter wave imaging is widely used in medical imaging scenarios.
  • the medical device transmits millimeter waves through the transmitting antenna, and the millimeter waves scan the biological surface at high speed and are reflected back. The medical device receives the reflected echo through the receiving antenna. Then, the medical device can reconstruct the image of the biological tissue based on the echo information. These images can be used for medical analysis, etc.
  • FIG1 shows a schematic diagram of a beam scanning system provided according to an embodiment of the present specification.
  • the beam scanning system 001 (hereinafter referred to as system 001) can be applied to any beam scanning scenario, such as a millimeter wave radar in an autonomous driving scenario, a millimeter wave imaging device in a medical imaging scenario, etc.
  • the system 001 may include an antenna module 100 and a signal processing circuit 200.
  • the antenna module 100 may include N transmitting antennas 10 arranged along a first direction in a first plane.
  • N is an integer greater than 1.
  • the first plane may be any plane in free space, and the first direction may be any direction in the first plane.
  • FIG. 2 shows a schematic diagram of the beam scanning system shown in FIG. 1 performing beam scanning. As shown in FIG. 2, taking the spatial rectangular coordinate system O-xyz as an example, the first plane may be an xOz plane, and the first direction may be an x-axis direction.
  • FIG. 1 and FIG. 2 illustrate the case where two transmitting antennas 10 are arranged along a first direction in a first plane.
  • other numbers (e.g., 3, 4, 5, etc.) of transmitting antennas 10 may be arranged along a first direction in a first plane.
  • Each transmitting antenna 10 may extend along a second direction in the first plane.
  • the second direction may be any direction in the first plane different from the first direction.
  • the second direction may be perpendicular to the first direction.
  • the second direction may be a z-axis direction, that is, each transmitting antenna 10 extends along the z-axis direction.
  • the above-mentioned N transmitting antennas 10 may be the same antenna.
  • the present application does not limit the shape of the transmitting antenna 10, which may be a rectangle, a parallelogram, a circle, an ellipse, or any other shape.
  • the first direction may be the direction of the short axis of the transmitting antenna 10 (i.e., the x-axis direction)
  • the second direction may be the direction of the long axis of the transmitting antenna 10 (i.e., the z-axis direction).
  • the first direction and the second direction determine the first plane where the antenna module 100 is located.
  • the operating frequency band of the antenna module 100 may include 60 GHz-64 GHz.
  • any two adjacent transmitting antennas 10 in the antenna module 100 may be spaced a certain distance apart to avoid mutual interference between different transmitting antennas 10.
  • the distance between any two adjacent transmitting antennas 10 in the antenna module 100 is d1
  • the value of d1 may be approximately equal to ⁇ /2, that is, the difference between d1 and ⁇ /2 is within a preset range. In this way, on the one hand, the interference between adjacent transmitting antennas 10 can be minimized, and on the other hand, the distance between adjacent transmitting antennas 10 can be avoided to be too large, which facilitates the miniaturization design of the antenna module 100.
  • Each transmitting antenna 10 is configured to convert an electrical signal into a millimeter wave electromagnetic signal and radiate the millimeter wave electromagnetic signal into free space. In this way, the N millimeter wave electromagnetic signals emitted by the N transmitting antennas 10 in the antenna module 100 interfere in free space to form a target beam.
  • the target beam refers to the main lobe beam in the radiation pattern corresponding to the antenna module 100.
  • the signal processing circuit 200 is connected to the antenna module 100 and is configured to output a frequency and phase controllable electrical signal to each of the N transmitting antennas.
  • the signal processing circuit 200 may be directly electrically connected to the antenna module 100, for example, each transmitting antenna 10 in the antenna module 100 is independently connected to the signal processing circuit 200.
  • the signal processing circuit 200 may also be indirectly electrically connected to the antenna module 100, for example, the signal processing circuit 200 is connected to a preset intermediate device, and the preset intermediate device is independently connected to each transmitting antenna 10 in the antenna module 100.
  • the signal processing circuit 200 may include a signal generator, a phase controller, and a frequency controller.
  • the signal processing circuit 200 may first generate a reference electrical signal through a signal generator, and then process the reference electrical signal through a phase controller and/or a frequency controller to obtain N electrical signals with controllable frequency and phase. Furthermore, the signal processing circuit 200 outputs the N electrical signals to the N transmitting antennas 10 one by one.
  • the frequency and phase of the N-channel electrical signals outputted by the signal processing circuit 200 can be adjusted to control the target beam to perform two-dimensional scanning.
  • target beam performs two-dimensional scanning means that the target beam can be scanned in a two-dimensional space.
  • the direction of the target beam can be scanned along the second plane and the third plane at the same time.
  • the second plane and the third plane are two mutually perpendicular planes in the free space.
  • the second plane and the third plane in the present application should not be understood as a specific plane, but should be understood as a series of parallel planes.
  • another way to express "the direction of the target beam scans along the second plane” can be “the direction of the target beam scans in the dimensional space determined by the second plane”
  • another way to express "the direction of the target beam scans along the third plane” can be “the direction of the target beam scans in the dimensional space determined by the third plane”.
  • the second plane may be any plane that satisfies the following conditions: perpendicular to the first plane and parallel to the second direction. It should be understood that when the first direction and the second direction are perpendicular to each other, the second plane is also perpendicular to the first direction.
  • the second plane may be a yOz plane or any plane parallel to the yOz plane.
  • the target beam when performing a two-dimensional scan, the target beam may scan all directions within the second plane or scan some directions within the second plane.
  • the scanning angle of the target beam in the second plane in FIG2 may be ⁇ .
  • the third plane may be any plane that satisfies the following conditions: perpendicular to the first plane and parallel to the first direction. It should be understood that when the first direction and the second direction are perpendicular to each other, the third plane is also perpendicular to the second direction.
  • the third plane may be an xOy plane or any plane parallel to the xOy plane.
  • the target beam when performing a two-dimensional scan, may scan all directions within the third plane or scan some directions within the third plane.
  • the scanning angle of the target beam in the third plane in FIG2 may be ⁇ .
  • the signal processing circuit 200 can control the direction of the target beam to scan along the second plane by adjusting the frequency of the N-channel electrical signals to change within a preset frequency band. In this case, the frequency of the electrical signal output by the signal processing circuit 200 to each transmitting antenna 10 changes over time within a preset frequency band.
  • the signal processing circuit 200 can adjust the frequency of the N-channel electrical signals synchronously (that is, the frequencies of the N-channel electrical signals output by the signal processing circuit 200 at the same time are the same), or can adjust asynchronously (that is, the frequencies of the N-channel electrical signals output by the signal processing circuit 200 at the same time are different), and this application is not limited to this.
  • the above-mentioned preset frequency band can be the operating frequency band of the antenna module.
  • the signal processing circuit 200 can adjust the frequency of the N-channel electrical signals within the frequency band range of 60GHz-64GHz.
  • Each transmitting antenna 10 in the antenna module 100 may be an antenna having the characteristic of performing beam scanning with frequency (i.e., the beam direction changes with frequency). In this way, when the frequency of the electrical signal received by the transmitting antenna 10 changes, the beam direction it emits will also change accordingly.
  • each transmitting antenna 10 may be a leaky wave antenna. The specific structure of the leaky wave antenna can be found in the introduction of the relevant content below, and will not be described in detail here.
  • each transmitting antenna 10 corresponds to K radiation units 11 along the second direction, where K is an integer greater than 1.
  • Each radiation unit 11 refers to a component that can radiate millimeter-wave electromagnetic signals into free space.
  • Each radiation unit 11 is configured to convert part of the electrical signal into a millimeter-wave electromagnetic signal.
  • K slots can be sequentially arranged in the transmitting antenna 10 along the second direction. When the transmitting antenna 10 is working, the leakage millimeter-wave electromagnetic signals of the K slot parts form the K radiation units.
  • the two transmitting antennas 10 in FIG2 are referred to as the first transmitting antenna and the second transmitting antenna in order from left to right.
  • the K radiating elements 11 on each transmitting antenna 10 are referred to as the first radiating element, the second radiating element, ..., the Kth radiating element in order along the z-axis direction.
  • each radiating unit 11 thereon converts part of the electrical signal into a millimeter wave electromagnetic signal and radiates the millimeter wave electromagnetic signal into free space.
  • the K-1th radiating unit and the Kth radiating unit both radiate millimeter wave electromagnetic signals into free space, and there is a first phase difference between the millimeter wave electromagnetic signals emitted by the two.
  • the millimeter wave electromagnetic signals emitted by the K-1th radiating unit and the Kth radiating unit interfere in free space to form a beam, and the beam is directed in a certain direction along the second plane (yOz plane or a plane parallel to the yOz plane).
  • the first phase difference between the millimeter wave electromagnetic signals emitted by the K-1th radiating unit and the Kth radiating unit changes.
  • the millimeter wave electromagnetic signals emitted by the K-1th radiation unit and the Kth radiation unit interfere in the free space to form a beam, and the direction of the beam changes along the second plane.
  • the beam radiated by the K-1th radiation unit and the Kth radiation unit can scan within a preset angle range (for example, ⁇ ) along the second plane.
  • FIG2 only shows the situation where the K-1th radiation unit and the Kth radiation unit of the second transmitting antenna emit millimeter wave electromagnetic signals and form a beam. It should be understood that the radiation of the millimeter wave electromagnetic signals by other radiation units (the 1st radiation unit to the K-2th radiation unit) in the transmitting antenna is similar. In this way, the millimeter wave electromagnetic signals emitted by all the radiation units 11 in the transmitting antenna interfere in the free space and form a beam, and the direction of the beam also scans along the second plane.
  • the signal processing circuit 200 can control the direction of the target beam to scan along the third plane by adjusting the second phase difference between the N electrical signals. For example, the signal processing circuit 200 can adjust the phase of the N electrical signals so that the electrical signals received by any two adjacent transmitting antennas 10 in the antenna module 100 have the same second phase difference.
  • the millimeter-wave electromagnetic signal emitted by the first radiating unit of the two transmitting antennas 10 interferes in free space to form a beam, and the direction of the beam can be along a certain direction of the third plane (xOy plane or a plane parallel to the xOy plane).
  • the second phase difference between the electrical signals received by the two transmitting antennas 10 changes, the millimeter-wave electromagnetic signal emitted by the first radiating unit of the two transmitting antennas 10 interferes in free space to form a beam, and the direction of the beam changes along the third plane.
  • the beam radiated by the first radiating unit of the two transmitting antennas 10 can be scanned along the third plane within a preset angle range (e.g., ⁇ ).
  • FIG. 2 only shows the situation where the first radiation unit in the two transmitting antennas 10 emits a millimeter-wave electromagnetic signal and forms a beam. It should be understood that the radiation of the millimeter-wave electromagnetic signal by other radiation units (the second radiation unit to the Kth radiation unit) in the two transmitting antennas 10 is also similar. In this way, the millimeter-wave electromagnetic signals emitted by all the radiation units 11 in the two transmitting antennas 10 interfere in the free space and form a beam, and the direction of the beam is also scanned along the third plane.
  • the signal processing circuit 200 can make the target beam emitted by the antenna module 100 (the beam formed by the interference of the millimeter-wave electromagnetic signals emitted by all the radiation units 11 in the N transmitting antennas) scan along the third plane by adjusting the second phase difference between the N electrical signals.
  • the present application scheme adopts a transmitting antenna 10 with a beam scanning characteristic with frequency, so that the antenna module 100 only needs to arrange multiple transmitting antennas 10 along one direction (first direction), and does not need to arrange multiple transmitting antennas 10 along other directions, so as to achieve two-dimensional scanning of the target beam.
  • first direction the spatial resolution and beam scanning range obtained by "arranging one transmitting antenna 10 along the first direction” can be equivalent to the effect achieved by "arranging dozens of traditional transmitting antennas along the second direction”. Therefore, the present application scheme greatly reduces the number of transmitting antennas 10 in the antenna module 100 while achieving the same scanning effect. It can be seen that the present application scheme can achieve two-dimensional scanning of the target beam when a small number of transmitting antennas 10 are arranged.
  • the beam scanning system can achieve two-dimensional scanning of the target beam at a low cost.
  • the transmitting antenna 10 in the present application may adopt a leaky wave antenna, and the structure of the leaky wave antenna is described below.
  • Fig. 3 shows a front view of a leaky wave antenna provided according to an embodiment of the present specification
  • Fig. 4 shows a side view of the leaky wave antenna shown in Fig. 3
  • Fig. 5 shows an enlarged view of the A portion in Fig. 3
  • Fig. 6 shows a rear view of the leaky wave antenna shown in Fig. 3.
  • the leaky wave antenna 600 can be used as the transmitting antenna 10 in the system 001 shown in Figs. 1 and 2.
  • the leaky wave antenna 600 may include: a first metal sheet 620.
  • the leaky wave antenna 600 may also include a substrate 610 and a second metal sheet 630.
  • the substrate 610 may include a first surface and a second surface disposed opposite to each other.
  • the first metal sheet 620 may be disposed on the first surface of the substrate 610.
  • the second metal sheet 630 may be disposed on the second surface of the substrate 610.
  • the first metal sheet 620 and the second metal sheet 630 may both be made of copper foil.
  • the first metal sheet 620 serves as the radiation surface of the leaky wave antenna 600
  • the second metal sheet 630 may be configured to be grounded.
  • the leaky wave antenna 600 may adopt a substrate integrated waveguide (SIW) structure.
  • the substrate 610 may be a printed circuit board (PCB).
  • the first metal sheet 620 and the second metal sheet 630 may be formed on both surfaces of the substrate 610 by a printing process.
  • the leaky wave antenna 600 may further include a plurality of metallized through holes 622.
  • the plurality of metallized through holes 622 may be periodically arranged along the edge of the first metal sheet 620.
  • Each metallized through hole 622 passes through the first metal sheet 620, the substrate 610, and the second metal sheet 630. Since the second metal sheet 630 is configured to be grounded, and the metallized through hole 622 passes through the first metal sheet 620, the substrate 610, and the second metal sheet 630, the first metal sheet 620 and the second metal sheet 630 are electrically connected.
  • the first metal sheet 620, the second metal sheet 630, and the plurality of metallized through holes 622 form a closed space similar to a metal waveguide, so that the millimeter wave electromagnetic signal is confined to be conducted in the second direction in the closed space.
  • the first metal sheet 620 may be provided with a row of metallized through holes at two edges along the long axis direction, respectively.
  • the distance between the two rows of metallized through holes 622 is the effective waveguide width wg.
  • the waveguide width wg is related to the operating frequency band of the leaky wave antenna 600. For example, when the operating frequency band of the leaky wave antenna 600 is 60 GHz to 64 GHz, the waveguide width wg may be 2.1 mm or the error between the width wg and 2.1 mm may be within a preset range.
  • the present application does not limit the shape of the metallized through hole 622, for example, it can be circular, elliptical, square, etc.
  • Figures 3 to 6 are illustrated by taking a circular metallized through hole as an example.
  • the present application does not limit the radius r of the metallized through hole 622 and the distance ps1 between adjacent metallized through holes.
  • the multiple metallized through holes 622 can be arranged more densely, for example, the radius r of the metallized through hole 622 can be less than or equal to 0.3mm, and the distance ps1 between the center points of two adjacent metallized through holes 622 can be less than or equal to 1mm.
  • the radius r of the metallized through hole 622 can be 0.25mm, and the distance ps1 between the center points of two adjacent metallized through holes 622 can be 0.44mm. It should be understood that when the multiple metallized through holes 622 are arranged more densely, it is equivalent to forming a "metal wall" on the side of the waveguide, so the millimeter wave electromagnetic signal will not leak through the side of the waveguide, which can reduce energy loss.
  • the use of a traditional waveguide structure will make the waveguide volume too large and not easy to be miniaturized and integrated.
  • the present application realizes the leaky wave antenna 600 by using a substrate integrated waveguide process. On the one hand, it can reduce the waveguide volume and facilitate the miniaturization design of the antenna. On the other hand, energy is not easy to leak to the outside through the side of the waveguide, and will not interfere with the external radiation source. In addition, its own anti-interference ability is also stronger.
  • K slots 621 are sequentially arranged on the first metal sheet 620 along the second direction, and the second direction is the extension direction of the leaky wave antenna 600.
  • the multiple metallized through holes 622 surround the K slots 621.
  • the leaky wave antenna 600 receives an electrical signal from the signal processing circuit 200 and converts the electrical signal at least partially into a millimeter wave electromagnetic signal.
  • the millimeter wave electromagnetic signal is conducted in the leaky wave antenna 600 along the second direction.
  • the K slots 621 partially leak the millimeter wave electromagnetic signal, so that the K slots 621 form K radiation units.
  • the slot 621 forms a capacitor in the propagation direction (i.e., the second direction) of the millimeter wave electromagnetic signal, which has an obstruction and retention effect (i.e., a slow wave effect) on the propagation of the millimeter wave electromagnetic signal, slowing down the propagation speed of the millimeter wave electromagnetic signal.
  • an obstruction and retention effect i.e., a slow wave effect
  • the first phase difference between the millimeter wave electromagnetic signals leaked by two adjacent slots 621 also changes significantly, so that the direction of the beam also changes significantly, thereby improving the scanning rate of the leaky wave antenna.
  • the shape of the slot 621 may be an elongated strip.
  • the width ws of the slot 621 may be less than a preset threshold value, which may depend on the antenna processing technology. That is, the width ws of the slot 621 may be as narrow as possible if the processing technology allows, for example, the width ws of the slot 621 may be less than or equal to 0.3 mm. In some embodiments, the width ws of the slot 621 may be 0.1 mm.
  • the distance ps2 between the central axes of any two adjacent slots 621 may also be less than a specified threshold value. For example, ps2 may be less than or equal to 1 mm.
  • ps2 may be 0.22 mm. It should be understood that when the width ws of the slot 621 is narrower and the distance ps2 between the central axes of two adjacent slots 621 is smaller, it is convenient to set more and denser slots 621 on the leaky wave antenna 600. Based on the previous description, when the slots 621 are more and denser, the slow wave effect is more obvious, thereby improving the scanning rate of the leaky wave antenna.
  • the edge of the slot 621 can be a smooth edge.
  • the shape of the slot 621 can be a rounded rectangle, so that there are no sharp corners on the edge of the slot 621. It should be understood that, under normal circumstances, the impedance formed by the sharp corners is large. When current flows near the sharp corners, the electric field will be enhanced, resulting in a large energy loss. Therefore, the present application can reduce the energy loss of the leaky wave antenna 600 as much as possible by setting the edge of the slot 621 to a smooth edge, and improve the radiation performance of the leaky wave antenna 600 in the millimeter wave frequency band.
  • the extension direction of the slot 621 may be a first direction.
  • the direction of the electric field formed by the slot 621 is perpendicular to the propagation direction (second direction) of the millimeter wave electromagnetic signal.
  • the extension direction of the slot 621 may also form a non-zero preset angle with the first direction. For example, the angle between the extension direction of the slot 621 and the first direction may be 45°.
  • the direction of the electric field formed by the slot 621 is no longer perpendicular to the propagation direction (second direction) of the millimeter wave electromagnetic signal, so that the polarization direction of the leaky wave antenna 600 changes. Therefore, in practical applications, the extension direction of the slot 621 can be designed according to the requirements of the application scenario for the polarization direction.
  • the leaky wave antenna 600 may include a long axis extending along the second direction.
  • a first reference line 623 and a second reference line 624 are provided on both sides of the long axis of the leaky wave antenna 600.
  • the first reference line 623 and the second reference line 624 are located inside the waveguide region surrounded by the plurality of metal vias 322.
  • the two ends of each slot 621 are located on the first reference line 623 and the second reference line 624, respectively.
  • the first reference line 623 and the second reference line 624 are not physical lines actually existing on the leaky wave antenna 600, but should be understood as two virtual lines.
  • the first reference line 623 is a virtual line obtained by fitting the first ends of the K slots 621
  • the second reference line 624 is a virtual line obtained by fitting the second ends of the K slots 621.
  • the first reference line 623 and the second reference line 624 are non-straight lines extending along the second direction, respectively. Since the first reference line 623 and the second reference line 624 are both non-straight lines, the K slots 621 are misaligned along the first direction (for example, the two ends of two adjacent slots 621 or several adjacent slots 621 are not aligned), so that the K slots 621 can radiate millimeter wave electromagnetic signals into free space.
  • the first reference line 623 and the second reference line 624 may be a broken line, for example, a triangular wave broken line, a square wave broken line, or any other type of broken line.
  • the first reference line 623 and the second reference line 624 may be smooth curves, such as a sine curve, a cosine curve, a quasi-sine curve, a quasi-cosine curve, or any other type of smooth curve. It can be understood that when the first reference line 623 and the second reference line 624 are smooth curves, there will be no sharp corners in the area where the current flows through, which can reduce energy loss, so that the energy loss of the leaky wave antenna 600 when working is less than a preset threshold.
  • the leaky wave antenna 600 when the leaky wave antenna 600 is applied to the millimeter wave frequency band, the first reference line 623 and the second reference line 624 can be designed as a smooth curve to reduce the energy loss in the medium propagation stage as much as possible, so that the leaky wave antenna 600 also has high radiation performance in the millimeter wave frequency band.
  • both the first reference line 623 and the second reference line 624 can be periodic target curves or target broken lines.
  • FIG. 3 illustrates the case where both the first reference line 623 and the second reference line 624 use periodic sine curves.
  • the period length ps3 of the target curve or target broken line (that is, the length of the target curve or target broken line of each period in the second direction) is related to the operating frequency band of the leaky wave antenna 600. Generally, the higher the operating frequency band of the leaky wave antenna 600, the smaller the period length of the target curve or target broken line.
  • the period length ps3 of the target curve or target broken line can be 1.76 mm, or the difference between ps3 and 1.76 mm is within a preset error range.
  • the first reference line 623 and the second reference line 624 adopt a periodic design so that the millimeter wave electromagnetic signal can be radiated through multiple cycles during the conduction process, thereby improving the energy radiation rate.
  • the antenna length can be designed based on the preset target energy radiation rate.
  • the value of x is increased successively, and the energy radiation rate of the antenna is tested.
  • the antenna length is determined based on the current value of x.
  • the first reference line 623 and the second reference line 624 are asymmetric along the long axis of the leaky wave antenna 600.
  • the long axis here may refer to the central axis of the leaky wave antenna 600 along the second direction, or may be another axis parallel to the central axis.
  • the first reference line 623 and the second reference line 624 are both sinusoidal curves, and there is a certain misalignment between the two in the long axis direction (that is, there is a preset phase difference between the two in the long axis direction), so that the two are asymmetric along the long axis.
  • the preset phase difference enables the leaky wave antenna to scan continuously in the direction where the side-fire angle is 0°.
  • the beam radiated by the leaky wave antenna 600 will produce a side-shooting stopband effect, that is, there is a scanning blind spot in the direction where the side-shooting angle is 0°, so that the side-shooting scanning range of the beam is not continuous.
  • the present application can eliminate the side-shooting stopband effect by asymmetrically designing the first reference line 623 and the second reference line 624, so that the beam can also scan to the direction where the side-shooting angle is 0°, so that the side-shooting scanning range of the beam is continuous, thereby expanding the side-shooting scanning range of the beam.
  • FIG7 shows a radiation pattern of a beam scanning system provided in the yOz plane according to an embodiment of the present specification
  • FIG8 shows a radiation pattern of a beam scanning system provided in the xOy plane according to an embodiment of the present specification.
  • the beam scanning system includes an antenna module and a signal processing circuit.
  • the antenna module uses three leaky wave antennas 600 arranged in sequence along the x-axis direction in the xOz plane, and the extension direction of each leaky wave antenna 600 is the z-axis direction.
  • the structure of each leaky wave antenna 600 is shown in FIG3 to FIG6, and the parameters of the leaky wave antenna 600 are as follows:
  • the width of the gap ws 0.1 mm;
  • the radius of the metallized through hole r 0.25 mm;
  • the effective waveguide width wg 2.1 mm.
  • the operating frequency band of the leaky wave antenna 600 is 60 GHz to 64 GHz.
  • the signal processing circuit provides one electrical signal to each of the three leaky wave antennas 600, and adjusts the frequency of the three electrical signals to continuously change within the above operating frequency band, and adjusts the phase difference between the three electrical signals.
  • the direction of the target beam radiated by the antenna module is collected to obtain the radiation pattern shown in Figures 7 and 8.
  • the signal processing circuit adjusts the phase difference between the three electrical signals so that the scanning range of the target beam along the xOy plane can reach 90°.
  • the beam scanning system includes an antenna module and a signal processing circuit, wherein the antenna module includes N transmitting antennas arranged along a first direction in a first plane, N is an integer greater than 1, each transmitting antenna extends along a second direction of the first plane, and is configured to convert an electrical signal into a millimeter wave electromagnetic signal, and the N millimeter wave electromagnetic signals emitted by the N transmitting antennas form a target beam; the signal processing circuit is connected to the antenna module, and when working, it outputs a frequency and phase controllable electrical signal to the N transmitting antennas to control the target beam for two-dimensional scanning.
  • the antenna module includes N transmitting antennas arranged along a first direction in a first plane, N is an integer greater than 1, each transmitting antenna extends along a second direction of the first plane, and is configured to convert an electrical signal into a millimeter wave electromagnetic signal, and the N millimeter wave electromagnetic signals emitted by the N transmitting antennas form a target beam;
  • the signal processing circuit is connected to the antenna module,
  • the present application scheme can adjust the frequency and phase of the electrical signal output to the N transmitting antennas through the signal processing circuit when the antenna module arranges multiple transmitting antennas only in one direction (first direction), so as to realize the two-dimensional scanning of the target beam.
  • the number of transmitting antennas in the antenna module is reduced, and accordingly, the number of channels working with the transmitting antennas will also be reduced, thereby reducing costs.
  • the beam scanning system provided by the present application can realize two-dimensional scanning of the target beam at a low cost.

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Abstract

本申请提供一种波束扫描***，包括天线模组和信号处理电路，其中，天线模组包括在第一平面内沿第一方向排布的N个发射天线，N为大于1的整数，每个发射天线沿第一平面的第二方向延伸，并被配置为将电信号转化成毫米波电磁信号，N个发射天线发出的N个毫米波电磁信号形成目标波束；信号处理电路与天线模组连接，工作时通过为N个发射天线分别输出一路频率及相位可控的电信号，来控制目标波束进行二维扫描。由此可见，本申请方案能够在天线模组仅沿一个方向(第一方向)排布多个发射天线的情况下，通过信号处理电路调整向N个发射天线输出的电信号的频率和相位，实现目标波束的二维扫描，因此能够低成本地实现目标波束的二维扫描。

Description

波束扫描*** 技术领域
本说明书涉及无线技术领域，尤其涉及一种波束扫描***。
背景技术
随着5G技术的发展，波束赋形技术得到广泛应用。利用波束赋形技术，天线模组能够实现对指定的方向(或者方向范围)进行波束扫描。一些应用场景(例如自动驾驶、医学成像等)要求电子设备(例如雷达)的天线模组具有二维空间的波束扫描能力，以便电子设备能够生成具有较高分辨率的图像。
相关技术为了实现二维空间的波束扫描，需要在至少两个维度上分别排布多个天线。例如，波束扫描***沿第一方向排布多个天线，通过这些天线实现一个空间维度的波束扫描；波束扫描***沿第二方向也排布多个天线，通过这些天线实现另一个空间维度的波束扫描。由此可见，上述相关技术需要在波束扫描***中设置较多数量的天线，相应的，还需要针对每个天线分别设置单独的发射/接收通道(比如低噪声放大器、混频器、中频滤波器、以及模数转换器/数模转换器等)来处理信号。应理解，在天线数量较多的情况下，通道的数量也很多，导致波束扫描***的成本大幅增加。
发明内容
本说明书提供一种波束扫描***，能够低成本地实现二维空间的波束扫描。
第一方面，本说明书提供一种波束扫描***，包括：天线模组和信号处理电路，其中，所述天线模组包括在第一平面内沿第一方向排布的N个发射天线，所述N为大于1的整数，每个所述发射天线沿所述第一平面的第二方向延伸，并被配置为将电信号转化成毫米波电磁信号，所述N个发射天线发出的N个所述毫米波电磁信号形成目标波束；所述信号处理电路与所述天线模组连接，工作时通过为所述N个发射天线分别输出一路频率及相位可控的所述电信号，控制所述目标波束进行二维扫描。
在一些实施例中，为了控制所述目标波束进行二维扫描，所述信号处理电路通过调整所述N路电信号的频率在预设频段内变化，来控制所述目标波束的指向沿第二平面扫描。
在一些实施例中，所述第二平面与所述第一平面垂直，且与所述第二方向平行。
在一些实施例中，每个所述发射天线沿所述第二方向对应有K个辐射单元，每个所述辐射单元将所述电信号部分的转化为所述毫米波电磁信号，所述K为大于1的整数；其中，任意相邻的两个所述辐射单元发出的所述毫米波电磁信号之间具有第一相位差，且所述第一相位差随所述电信号的频率变化而变化，使得所述目标波束的指向沿所述第二平面扫描。
在一些实施例中，每个所述发射天线包括沿所述第二方向延伸的长轴，且在所述长轴的两侧对应有第一参考线和第二参考线，所述第一参考线和所述第二参考线分别为沿所述第二方向延伸的非直线；以及每个所述辐射单元的两端分别位于所述第一参考线和所述第二参考线上。
在一些实施例中，所述第一参考线和所述第二参考线分别为光滑曲线，使得所述发射天线工作时的能量损耗小于预设阈值。
在一些实施例中，所述第一参考线和所述第二参考线均为周期性的目标曲线或者目标折线。
在一些实施例中，所述第一参考线和所述第二参考线沿所述长轴不对称。
在一些实施例中，每个所述发射天线包括第一金属片，所述第一金属片上沿所述第二方向依次设置有K个缝隙；其中，在所述发射天线工作时，所述K个缝隙部分地泄露所述毫米波电磁信号形成所述K个辐射单元。
在一些实施例中，每个所述缝隙的边缘为光滑边缘。
在一些实施例中，每个所述发射天线还包括：基板、第二金属片以及多个金属化通孔；其中，所述基板包括相背设置的第一面和第二面，所述第一金属片设置在所述第一面上；所述第二金属片设置在所述第二面上，被配置为接地；每个所述金属化通孔均贯通所述第一金属片、所述基板和所述第二金属片，且所述多个金属化通孔包围所述K个缝隙。
在一些实施例中，为了控制所述目标波束进行二维扫描，所述信号处理电路通过调整所述N路电信号之间的第二相位差，来控制所述目标波束的指向沿第三平面扫描。
在一些实施例中，所述第三平面与所述第一平面垂直，且与所述第一方向平行。
在一些实施例中，所述天线模组的工作波长为λ，所述天线模组中任意两个相邻的所述发射天线之间的距离为d1，所述d1与λ/2之间的差值在预设范围内。
在一些实施例中，所述天线模组的工作频段包括：60GHz-64GHz。
由以上技术方案可知，本说明书提供的波束扫描***，包括天线模组和信号处理电路，其中，天线模组包括在第一平面内沿第一方向排布的N个发射天线，N为大于1的整数，每个发射天线沿第一平面的第二方向延伸，并被配置为将电信号转化成毫米波电磁信号，N个发射天线发出的N个毫米波电磁信号形成目标波束；信号处理电路与天线模组连接，工作时通过为N个发射天线分别输出一路频率及相位可控的电信号，来控制目标波束进行二维扫描。由此可见，本申请方案能够在天线模组仅沿一个方向(第一方向)排布多个发射天线的情况下，通过信号处理电路调整向N个发射天线输出的电信号的频率和相位，实现目标波束的二维扫描。相比相关技术需要在多个方向均布设多个发射天线而言，减少了天线模组中的发射天线的数量，相应的，配合发射天线工作的通道的数量也会减少，从而能够降低成本。也就是说，本申请提供的波束扫描***能够在低成本的情况下，实现目标波束的二维扫描。
本说明书提供的波束扫描***的其他功能将在以下说明中部分列出。本说明书提供的波束扫描***的创造性方面可以通过实践或使用下面详细示例中所述的方法、装置和组合得到充分解释。
附图说明
为了更清楚地说明本说明书实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本说明书的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1示出了根据本说明书的实施例提供的一种波束扫描***的示意图；
图2示出了图1所示的波束扫描***进行波束扫描的示意图；
图3示出了根据本说明书的实施例提供的一种漏波天线的正视图；
图4示出了图3所示漏波天线的侧视图；
图5示出了图3中的A部的放大图；
图6示出了图3所示漏波天线的后视图；
图7示出了根据本说明书的实施例提供的波束扫描***在yOz平面的辐射方向图；以及
图8示出了根据本说明书的实施例提供的波束扫描***在xOy平面的辐射方向图。
具体实施方式
以下描述提供了本说明书的特定应用场景和要求，目的是使本领域技术人员能够制造和使用本说明书中的内容。对于本领域技术人员来说，对所公开的实施例的各种局部修改是显而易见的，并且在不脱离本说明书的精神和范围的情况下，可以将这里定义的一般原理应用于其他实施例和应用。因此，本说明书不限于所示的实施例，而是与权利要求一致的最宽范围。
这里使用的术语仅用于描述特定示例实施例的目的，而不是限制性的。比如，除非上下文另有明确说明，这里所使用的，单数形式“一”，“一个”和“该”也可以包括复数形式。当在本说明书中使用时，术语“包括”、“包含”和/或“含有”意思是指所关联的整数，步骤、操作、元素和/或组件存在，但不排除一个或多个其他特征、整数、步骤、操作、元素、组件和/或组的存在或在该***/方法中可以添加其他特征、整数、步骤、操作、元素、组件和/或组。
考虑到以下描述，本说明书的这些特征和其他特征、以及结构的相关元件的操作和功能、以及部件的组合和制造的经济性可以得到明显提高。参考附图，所有这些形成本说明书的一部分。然而，应该清楚地理解，附图仅用于说明和描述的目的，并不旨在限制本说明书的范围。还应理解，附图未按比例绘制。
本说明书中使用的流程图示出了根据本说明书中的一些实施例的***实现的操作。应该清楚地理解，流程图的操作可以不按顺序实现。相反，操作可以以反转顺序或同时实现。此外，可以向流程图添加一个或多个其他操作。可以从流程图中移除一个或多个操作。
为了方便描述，首先对本说明书描述中将会出现的术语进行如下解释：
波束赋形，又叫波束成型、空域滤波，是一种使用天线阵列定向发送和接收信号的信号处理技术。波束赋形技术通过调整天线阵列中天线单元的参数，使得某些角度的信号获得相长干涉，而另一些角度的信号获得相消干涉，最终形成定向的波束。波束赋形既可以用于信号发射端，又可以用于信号接收端。
天线方向图，又叫辐射方向图，是指在离天线一定距离处，辐射场的相对场强(归一化模值)随方向变化的图形，通常采用通过天线最大辐射方向上的两个相互垂直的平面方向图来表示。天线方向图通常都有两个或多个瓣，其中辐射强度最大的瓣称为主瓣，其余的瓣称为副瓣或旁瓣，与主瓣相反方向上的旁瓣叫后瓣。
波束，在本文中是指天线方向图的主瓣，也就是天线辐射能力最集中的部分。波束的形状可以是任意的，由天线采用的波束赋形技术决定。
波束的指向，是指波束所指向的方向，也可以称为波束的发射方向，或者称为波束的扫描方向。例如，当波束为瓣状时，波束的指向可以具体是指波束的中轴线(即能量最集中的部分)所指向的方向。
毫米波，波长为1～10毫米(频率范围为30～300GHz)的电磁波可以称为毫米波。毫米波位于微波与远红外波相交叠的波长范围，因而兼有两种波谱的特点。与红外波相比，毫米波的波束很窄，能更精准地分辨目标物并还原目标物细节。与激光相比，毫米波受天气和外界环境(例如雨雪、灰尘、阳光等)的变化的影响小，对气候要求更低。与微波相比，毫米波元器件尺寸更小，毫米波设备更容易小型化。
漏波天线，当电磁波沿行波结构传播时，若沿此结构不断地产生辐射，所辐射的波被称为漏波。这种产生漏波的结构被称为漏波天线。漏波天线是一种行波天线。行波天线指的是馈入的电磁场会呈现行波状态分布的天线。漏波天线除了继承行波天线宽带的特点，还具有随频率进行波束扫描的特性，即波束的指向随着频率变化而变化。漏波天线通常由波导壁上开周期性缝隙形成。漏波天线在工作时波导内部传输的电磁波信号不断地从波导壁上的周期性缝隙处漏泄出来从而产生辐射，形成高指向性、可频率控制的波束扫描的辐射方向图。
漏波天线的扫描率，用于表征漏波天线发出的波束(主瓣)的扫描角度随频率变化的快慢程度。本申请可以将漏波天线发出的波束的扫描角度的变化Δθ与频率变化Δf之间的比率，作为漏波天线的扫描率。当漏波天线的扫描率较高时，说明漏波天线的波束指向随频率变化较为灵敏，即，频率变化一个较小的值，即可使得波束扫过较大的角度。因此，漏波天线的扫描率也可以称为漏波天线对频率变化的灵敏度。
天线阵列，将两个或两个以上的单体天线，按照一定的要求进行馈电和空间排列构成的天线***称为天线阵列，也可以称为天线阵。天线阵列的辐射场是各单体天线的辐射场的矢量和，其特性取决于单体天线的形式、位置、排列方式及其激励幅度和相位。
端射方向和边射方向，如果天线的最大辐射方向与天线平行，则该最大辐射方向为端射方向；如果天线的最大辐射方向与天线垂直，则该最大辐射方向为边射方向。
在对本说明书具体实施例说明之前，先对本说明书的应用场景进行如下介绍：
自动驾驶场景：毫米波雷达具有波长短、设备体积小等特点，并且在探测精度、探测距离等方面具有明显优势，因此，在自动驾驶场景中发挥着十分重要的作用。毫米波雷达设置有发射天线和接收天线。发射天线能够发射具有指向性的毫米波。当毫米波遇到障碍物后反射回来，接收天线接收反射回来的回波。这样，雷达根据发射天线发射毫米波的时刻、接收天线接收回波的时刻、以及车辆的行驶速度等因素，可以确定出障碍物的位置。雷达还可以根据发射天线发射毫米波的频率、相位等信息，以及接收天线接收回波的频率、相位等信息，确定出障碍物的速度、方位角等信息。可见，毫米波雷达能帮助车辆准确感知周围环境，敏捷的识别周边障碍物与车辆的距离、角度、速度等信息，保证车辆的安全行驶。
医疗成像场景：毫米波成像的原理是用毫米波照射被测物体，然后基于被测物体外部散射场的测量值来重构被测物体的形状或介电常数分布。由于介电常数大小与生物组织含水量密切相关，故毫米波成像非常适合对生物组织进行成像，因此，毫米波成像被广泛应用于医疗成像场景。该场景下，医疗设备通过发射天线发射毫米波，毫米波高速扫描生物表面并被反射回来。医疗设备通过接收天线接收反射回来的回波。进而，医疗设备基于回波信息可以重构出生物组织的图像。这些图像可被用于医学分析等。
需要说明的是，上述自动驾驶、医疗成像场景只是本说明书提供的多个使用场景中的部分场景，本说明书提供的波束扫描***不仅可以应用于自动驾驶、医疗成像场景，还可以应用于毫米波通信的所有场景，例如基于毫米波的安检场景等。本领域技术人员应当明白，本说明书所述的波束扫描***应用于其他使用场景也在本说明书的保护范围内。
图1示出了根据本说明书的实施例提供的一种波束扫描***的示意图。波束扫描***001(以下简称***001)可以应用于任意的波束扫描场景，比如，自动驾驶场景下的毫米波雷达，医疗成像场景下的毫米波成像设备，等等。如图1所示，***001可以包括天线模组100和信号处理电路200。
其中，天线模组100可以包括在第一平面内沿第一方向排布的N个发射天线10。N为大于1的整数。第一平面可以为自由空间中的任意平面，第一方向可以为第一平面内 的任意方向。图2示出了图1所示的波束扫描***进行波束扫描的示意图。如图2所示，以空间直角坐标系O-xyz为例，第一平面可以为xOz平面，第一方向可以为x轴方向。图1和图2示例的是在第一平面内沿第一方向排布有2个发射天线10的情况。在一些实施例中，在第一平面内沿第一方向可以排布其他数量(例如3、4、5等)的发射天线10。每个发射天线10可以沿第一平面内的第二方向延伸。第二方向可以是第一平面内与第一方向不同的任意方向。在一些实施例中，第二方向可以与第一方向垂直。例如，参见图2，第二方向可以为z轴方向，即每个发射天线10沿z轴方向延伸。上述N个发射天线10可以为相同的天线。
需要说明的是，本申请对于发射天线10的形状不作限定，可以为矩形、平行四边形、圆形、椭圆形、或者其他任意形状等。参见图2，当发射天线10为矩形时，第一方向可以为发射天线10的短轴线方向(即x轴方向)，第二方向可以为发射天线10的长轴线方向(即z轴方向)。第一方向和第二方向决定了天线模组100所在的第一平面。
在一些实施例中，天线模组100的工作频段可以包括60GHz-64GHz。
如图1所示，天线模组100中的任意两个相邻的发射天线10之间可以间隔一定距离，以避免不同发射天线10之间相互干扰。在一些实施例中，假设天线模组100的工作波长为λ，天线模组100中任意两个相邻的发射天线10之间的距离为d1，d1的取值可以近似等于λ/2，也就是说，d1与λ/2之间的差值在预设范围内。这样，一方面可以尽量降低相邻发射天线10之间的干扰，另一方面也可以避免相邻发射天线10之间的距离过大，便于天线模组100的小型化设计。
每个发射天线10被配置为将电信号转化成毫米波电磁信号，并将所述毫米波电磁信号辐射到自由空间。这样，天线模组100中的N个发射天线10发出的N个所述毫米波电磁信号在自由空间中进行干涉形成目标波束。其中，目标波束是指天线模组100对应的辐射方向图中的主瓣波束。
继续参见图1，信号处理电路200与天线模组100连接，被配置为向N个发射天线分别输出一路频率及相位可控的电信号。在一些实施例中，信号处理电路200可以与天线模组100直接电性连接，例如，天线模组100中的各发射天线10分别独立连接至信号处理电路200。在一些实施例中，信号处理电路200还可以与天线模组100间接电性连接，例如，信号处理电路200连接至预设中间设备，预设中间设备与天线模组100中的各发射天线10分别独立连接。在一些实施例中，信号处理电路200中可以包括信号 生成器、相位控制器和频率控制器。信号处理电路200可以先通过信号生成器生成基准电信号，然后通过相位控制器和/或频率控制器对上述基准电信号进行处理，得到频率及相位可控的N路电信号。进而，信号处理电路200向所述N个发射天线10一一对应的输出上述N路电信号。
信号处理电路200工作时可以通过调整其输出的N路电信号的频率及相位，控制目标波束进行二维扫描。其中，上述“目标波束进行二维扫描”是指目标波束可以在二维空间内进行扫描。例如，目标波束的指向可以同时沿第二平面和第三平面扫描。其中，第二平面和第三平面是自由空间中的两个相互垂直的平面。
需要说明的是，本申请中第二平面和第三平面不应理解为某个特定的平面，而应理解为相互平行的一系列平面。也就是说，“目标波束的指向沿第二平面扫描”的另一种表述方式可以为“目标波束的指向在第二平面所决定的维度空间内扫描”，“目标波束的指向沿第三平面扫描”的另一种表述方式可以为“目标波束的指向在第三平面所决定的维度空间内扫描”。
在一些实施例中，第二平面可以为满足下述条件的任意平面：与第一平面垂直、且与第二方向平行。应理解，在第一方向与第二方向相互垂直的情况下，第二平面还与第一方向垂直。例如，参见图2，第二平面可以为yOz平面或者为与yOz平面平行的任意平面。在一些实施例中，目标波束在进行二维扫描时，可以扫描第二平面内的所有方向，也可以扫描第二平面内的部分方向。例如，图2中目标波束在第二平面内的扫描角度可以为α。
在一些实施例中，第三平面可以为满足下述条件的任意平面：与第一平面垂直、且与第一方向平行。应理解，在第一方向与第二方向相互垂直的情况下，第三平面还与第二方向垂直。例如，参见图2，第三平面可以为xOy平面或者为与xOy平面平行的任意平面。在一些实施例中，目标波束在进行二维扫描时，可以扫描第三平面内的所有方向，也可以扫描第三平面内的部分方向。例如，图2中目标波束在第三平面内的扫描角度可以为θ。
在一些实施例中，信号处理电路200可以通过调整N路电信号的频率在预设频段内变化，来控制目标波束的指向沿所述第二平面扫描。该情况下，信号处理电路200向每个发射天线10输出的电信号的频率是随时间在预设频段内变化的。其中，信号处理电路200可以对N路电信号的频率进行同步调整(即，在同一时刻信号处理电路200输出 的N路电信号的频率相同)，也可以进行异步调整(即，在同一时刻信号处理电路200输出的N路电信号的频率不同)，本申请对此不作限定。上述预设频段可以为天线模组的工作频段。例如，当天线模组的工作频段为60GHz-64GHz时，信号处理电路200可以在60GHz-64GHz频段范围内调整N路电信号的频率。
天线模组100中的每个发射天线10可以为具有随频率进行波束扫描的特性(即波束指向随频率变化而变化)的天线。这样，当发射天线10接收到的电信号的频率发生变化后，其发出的波束指向也会随之发生变化。在一些实施例中，每个发射天线10可以为漏波天线。其中，漏波天线的具体结构可以参见后文相关内容的介绍，此处不作详细说明。
如图2所示，每个发射天线10沿第二方向对应有K个辐射单元11，K为大于1的整数。其中，每个辐射单元11是指能够向自由空间辐射毫米波电磁信号的部件。每个辐射单元11被配置为将电信号部分的转化为毫米波电磁信号。并且，任意相邻的两个辐射单元11发出的毫米波电磁信号之间具有第一相位差，所述第一相位差随电信号的频率变化而变化，使得目标波束的指向沿第二平面扫描。在一些实施例中，当发射天线10为漏波天线时，发射天线10沿第二方向可以依次设置K个缝隙。在发射天线10工作时，所述K个缝隙部分的泄露毫米波电磁信号形成所述K个辐射单元。
下面结合图2对目标波束的指向沿第二平面扫描进行举例说明。本说明书为了便于描述，将图2中的两个发射天线10按照从左到右的顺序依次称为第1个发射天线和第2个发射天线。并且，将每个发射天线10上的K个辐射单元11按照沿z轴方向的次序，依次称为第1个辐射单元，第2个辐射单元，……，第K个辐射单元。
以图2中的第2个发射天线10为例，该发射天线10从信号处理电路200接收到电信号后，其上的各辐射单元11将电信号部分的转化为毫米波电磁信号，并向自由空间辐射毫米波电磁信号。参见图1，以第K-1个辐射单元和第K个辐射单元为例，第K-1个辐射单元和第K个辐射单元均向自由空间辐射毫米波电磁信号，并且，二者发出的毫米波电磁信号之间具有第一相位差，因此，第K-1个辐射单元和第K个辐射单元所发出的毫米波电磁信号在自由空间发生干涉形成波束，该波束的指向为沿第二平面(yOz平面或与yOz平面平行的平面)的某个方向。当发射天线10接收到的电信号的频率发生变化时，第K-1个辐射单元和第K个辐射单元发出的毫米波电磁信号之间的第一相位差发生变化。此时，第K-1个辐射单元和第K个辐射单元所发出的毫米波电磁信号在自由 空间发生干涉形成波束，该波束的指向沿第二平面发生变化。随着发射天线10接收到的电信号的频率不断发生变化，第K-1个辐射单元和第K个辐射单元所辐射形成的波束可以沿第二平面在预设角度范围(例如α)内扫描。
需要说明的是，图2仅示出了第2个发射天线的第K-1个辐射单元和第K个辐射单元发出毫米波电磁信号并形成波束的情况。应理解的是，该发射天线中其他辐射单元(第1个辐射单元至第K-2个辐射单元)对毫米波电磁信号的辐射情况也是类似的。这样，该发射天线中所有的辐射单元11发出的毫米波电磁信号在自由空间发生干涉并形成波束，该波束的指向也沿第二平面扫描。
在一些实施例中，信号处理电路200可以通过调整N路电信号之间的第二相位差，来控制目标波束的指向沿所述第三平面扫描。例如，信号处理电路200可以调整N路电信号的相位，使得天线模组100中任意两个相邻的发射天线10接收到的电信号之间具有相同的第二相位差。
下面结合图2对目标波束的指向沿第三平面扫描进行举例说明。参见图2，当两个发射天线10接收到的电信号之间具有第二相位差时，这两个发射天线10中的第1个辐射单元发出的毫米波电磁信号在自由空间发生干涉形成波束，该波束的指向可以沿第三平面(xOy平面或与xOy平面平行的平面)的某个方向。当两个发射天线10接收到的电信号之间的第二相位差发生变化时，这两个发射天线10中的第1个辐射单元所发出的毫米波电磁信号在自由空间发生干涉形成波束，该波束的指向沿所述第三平面发生变化。随着两个发射天线10接收到的电信号之间的第二相位差不断发生变化，这两个发射天线10中的第1个辐射单元所辐射形成的波束可以沿所述第三平面在预设角度范围(例如θ)内扫描。
需要说明的是，图2中仅示出了两个发射天线10中的第1个辐射单元发出毫米波电磁信号并形成波束的情况。应理解的是，这两个发射天线10中其他辐射单元(第2个辐射单元至第K个辐射单元)对毫米波电磁信号的辐射情况也是类似的。这样，两个发射天线10中所有的辐射单元11发出的毫米波电磁信号在自由空间发生干涉并形成波束，该波束的指向也沿第三平面扫描。由此可见，信号处理电路200通过调整N路电信号之间的第二相位差，可以使得天线模组100发出的目标波束(N个发射天线中的所有辐射单元11所发出的毫米波电磁信号进行干涉形成的波束)的指向沿第三平面扫描。
本申请方案通过采用具有随频率进行波束扫描特性的发射天线10，使得天线模组 100只需要沿一个方向(第一方向)布设多个发射天线10，而无需沿其他方向布设多个发射天线10，即可实现目标波束的二维扫描。根据实际测试结果发现，“沿第一方向布设一个发射天线10”获得的空间分辨率和波束扫描范围能够与“沿第二方向布设数十个传统发射天线”达到的效果相当。因此，本申请方案在达到相同扫描效果的情况下，大幅降低了天线模组100中的发射天线10的数量。由此可见，本申请方案能够在布设较少数量的发射天线10的情况下，实现目标波束的二维扫描。能够理解，天线模组100中布设的发射天线10的数量较少时，配合发射天线10工作的通道的数量也会减少，因此，波束扫描***的成本能够大幅降低。由此可见，本申请提供的波束扫描***能够在低成本的情况下，实现目标波束的二维扫描。
如前所述，本申请中的发射天线10可以采用漏波天线，下面对漏波天线的结构进行说明。
图3示出了根据本说明书的实施例提供的一种漏波天线的正视图，图4示出了图3所示漏波天线的侧视图，图5示出了图3中的A部的放大图，图6示出了图3所示漏波天线的后视图。该漏波天线600可以作为图1和图2所示***001中的发射天线10。
如图3、图4、图5和图6所示，漏波天线600可以包括：第一金属片620。在一些实施例中，漏波天线600还可以包括基板610和第二金属片630。基板610可以包括相背设置的第一面和第二面。第一金属片620可以设置在基板610的第一面上。第二金属片630可以设置在基板610的第二面上。在一些实施例中，第一金属片620和第二金属片630均可以为铜箔材质。其中，第一金属片620作为漏波天线600的辐射面，第二金属片630可以被配置为接地。
漏波天线600可以采用基板集成波导(Substrate integrated waveguide，SIW)结构。在一些实施例中，基板610可以为印制电路板(Printed Circuit Board，PCB)板。例如，基板610可以采用Rogers RO 3003印制电路板，厚度h＝0.25mm，相对介电常数ε r＝3.0，损耗角δ的正切值tanδ＝0.001。第一金属片620和第二金属片630均可以通过印制工艺形成于基板610的两个表面。
在一些实施例中，漏波天线600还可以包括多个金属化通孔622。多个金属化通孔622可以沿着第一金属片620的边缘周期性设置。每个金属化通孔622均贯通第一金属片620、基板610和第二金属片630。由于第二金属片630被配置为接地，并且，金属化通孔622贯通第一金属片620、基板610和第二金属片630，因此，第一金属片620 和第二金属片630实现了电连接。这样，第一金属片620、第二金属片630以及多个金属化通孔622形成类似于金属波导的封闭空间，从而毫米波电磁信号被限制在该封闭空间中沿第二方向传导。在一些实施例中，如图3至图6所示，第一金属片620可以在沿长轴方向的两个边缘分别设置一排金属化通孔。两排金属化通孔622之间的距离为有效的波导宽度wg。通常，波导宽度wg与漏波天线600的工作频段相关。例如，当漏波天线600的工作频段为60GHz～64GHz时，波导宽度wg可以为2.1mm或者与2.1mm之间的误差在预设范围内。
需要说明的是，本申请对于金属化通孔622的形状不作限定，例如可以为圆形、椭圆形、方形等。图3至图6中以圆形的金属化通孔为例进行示意。另外，本申请对于金属化通孔622的半径r以及相邻金属化通孔之间的距离ps1不作限定。在一些实施例中，所述多个金属化通孔622可以设置的较为密集，例如，金属化通孔622的半径r可以小于或等于0.3mm，相邻两个金属化通孔622的中心点之间的距离ps1可以小于或等于1mm。在一些实施例中，金属化通孔622的半径r可以为0.25mm，相邻两个金属化通孔622的中心点之间的距离ps1可以为0.44mm。应理解，当多个金属化通孔622设置的较为密集时，相当于在波导的侧边形成了“金属壁”，因此，毫米波电磁信号不会通过波导的侧边发生泄露，能够降低能量损耗。
在毫米波频段的应用场景中，由于毫米波电磁信号的频率较高，采用传统的波导结构会使得波导体积过大，不易于小型化集成。本申请通过采用基板集成波导的工艺实现漏波天线600，一方面能够降低波导体积，便于天线小型化设计，另一方面能量不易通过波导侧边泄露到外部，不会对外界辐射源产生干扰，并且，自身的抗干扰能力也更强。
在一些实施例中，如图3所示，所述第一金属片620上沿第二方向依次设置有K个缝隙621，第二方向为漏波天线600的延伸方向。其中，所述多个金属化通孔622包围所述K个缝隙621。在漏波天线600工作时，漏波天线600从信号处理电路200接收电信号，并将电信号至少部分的转化为毫米波电磁信号。毫米波电磁信号在漏波天线600中沿第二方向传导。在毫米波电磁信号的传导过程中，所述K个缝隙621部分的泄露毫米波电磁信号，使得K个缝隙621形成K个辐射单元。
在漏波天线600工作时，缝隙621在毫米波电磁信号的传播方向(即第二方向)上形成电容，对毫米波电磁信号的传播产生阻碍、滞留的作用(即慢波效应)，减缓了毫米波电磁信号的传播速度。能够理解，缝隙621的数量越多、越密，这种慢波效应越明 显，使得相邻两个缝隙621所泄露的毫米波电磁信号之间的第一相位差对电信号的频率变化越敏感。也就是说，即使是在电信号的频率变化较小的情况下，相邻两个缝隙621所泄露的毫米波电磁信号之间的第一相位差也有明显变化，使得波束的指向也有明显变化，从而能够提高漏波天线的扫描率。
在一些实施例中，缝隙621的形状可以为细长的长条形。例如，缝隙621的宽度ws可以小于预设阈值，该预设阈值可以取决于天线加工工艺。也就是说，缝隙621的宽度ws可以在加工工艺允许的情况下尽可能的窄，例如，缝隙621的宽度ws可以小于或者等于0.3mm。在一些实施例中，缝隙621的宽度ws可以为0.1mm。另外，任意两个相邻的缝隙621的中轴线之间的距离ps2也可以小于某个指定阈值。例如，ps2可以小于或等于1mm。在一些实施例中，ps2可以为0.22mm。应理解，当缝隙621的宽度ws较窄、以及相邻两个缝隙621的中心轴线之间的距离ps2较小时，便于在漏波天线600上设置较多、较密的缝隙621。基于前面的描述，当缝隙621较多、较密时，慢波效应越明显，从而能够提高漏波天线的扫描率。
在实际应用中，由于毫米波波长短，容易受到大气中气体分子、水凝物和悬浮尘埃等的吸收和散射作用影响，路径损耗很严重。因此，在一些实施例中，当漏波天线600应用于毫米波频段时，缝隙621的边缘可以为光滑边缘。例如，缝隙621的形状可以为圆角矩形，这样，缝隙621的边缘不会存在尖角。应理解，通常情况下，尖角形成的阻抗较大，当尖角附近有电流流过时，会使得电场增强，产生较大的能量损耗。因此，本申请通过将缝隙621的边缘设置为光滑边缘，能够尽可能的降低漏波天线600的能量损耗，提高漏波天线600在毫米波频段的辐射性能。
需要说明的是，本申请对于缝隙621的延伸方向不作限定。在一些实施例中，如图3所示，缝隙621的延伸方向可以为第一方向。该情况下，缝隙621形成的电场方向与毫米波电磁信号的传播方向(第二方向)垂直。在一些实施例中，缝隙621的延伸方向还可以与第一方向之间形成非零的预设夹角。例如，缝隙621的延伸方向与第一方向之间的夹角可以为45°。该情况下，缝隙621形成的电场方向与毫米波电磁信号的传播方向(第二方向)不再垂直，使得漏波天线600的极化方向发生变化。因此，在实际应用中，可以根据应用场景对于极化方向的需求，来设计缝隙621的延伸方向。
在一些实施例中，如图3所示，漏波天线600可以包括沿第二方向延伸的长轴。在漏波天线600的长轴的两侧对应有第一参考线623和第二参考线624。第一参考线623 和第二参考线624位于由所述多个金属通孔322围成的波导区域内部。每个缝隙621的两端分别位于第一参考线623和第二参考线624上。需要说明的是，第一参考线623和第二参考线624并不是漏波天线600上实际存在的物理线条，而应理解为两条虚拟线。或者说，第一参考线623是由K个缝隙621的第一端拟合得到的虚拟线，第二参考线624是由K个缝隙621的第二端拟合得到的虚拟线。
第一参考线623和第二参考线624分别为沿第二方向延伸的非直线。由于第一参考线623和第二参考线624均为非直线，使得K个缝隙621在沿第一方向上存在错位(例如，相邻两个缝隙621或者邻近的若干个缝隙621的两端不对齐)，从而，K个缝隙621能够向自由空间辐射毫米波电磁信号。
在一些实施例中，第一参考线623和第二参考线624可以为折线，例如，三角波折线、方波折线或其他任意类型的折线。在一些实施例中，如图3所示，第一参考线623和第二参考线624均可以为光滑曲线，例如正弦曲线、余弦曲线、类正弦曲线、类余弦曲线，或者其他任意类型的光滑曲线。能够理解，当第一参考线623和第二参考线624为光滑曲线时，使得电流流过区域不会存在尖角，能够降低能量损耗，使得漏波天线600工作时的能量损耗小于预设阈值。在实际应用中，由于毫米波波长短，容易受到大气中气体分子、水凝物和悬浮尘埃等的吸收和散射作用影响，路径损耗很严重。因此，当漏波天线600应用于毫米波频段时，第一参考线623和第二参考线624可以设计为光滑曲线，尽可能地降低介质传播阶段的能量损耗，使得漏波天线600在毫米波频段也有较高辐射性能。
在一些实施例中，第一参考线623和第二参考线624均可以为周期性的目标曲线或者目标折线。例如图3示例的是第一参考线623和第二参考线624均采用周期性的正弦曲线的情况。其中，目标曲线或者目标折线的周期长度ps3(即每个周期的目标曲线或目标折线在第二方向上的长度)与漏波天线600的工作频段相关。通常情况下，漏波天线600的工作频带越高频，目标曲线或目标折线的周期长度越小。例如，当漏波天线600的工作频段为60GHz～64GHz时，目标曲线或目标折线的周期长度ps3可以为1.76mm，或者ps3与1.76mm之间的差值在预设误差范围内。第一参考线623和第二参考线624通过采用周期性设计，使得毫米波电磁信号在传导过程中能够经过多个周期的辐射，从而提高能量辐射率。
应理解的是，当第一参考线623和第二参考线624所包含的目标曲线/目标折线的周 期数量较多时，天线的能量辐射率较高，但是，天线长度也会较长，不利于天线的小型化设计。当第一参考线623和第二参考线624所包含的目标曲线/目标折线的周期数量较少时，天线长度较短，虽然利于天线的小型化设计，但是由于能量辐射率较低，剩余能量在天线末端形成反射，对会能量辐射形成干扰。因此，实际应用中可以基于预设的目标能量辐射率来设计天线长度。例如，假设目标曲线/目标折线的周期数量为x，依次增大x的取值，对天线的能量辐射率进行测试，当测得的能量辐射率大于或等于预设的目标能量辐射率时，基于当前x的取值确定天线长度。例如，上述预设的目标能量辐射率可以为90％。需要说明的是，图3仅以周期数量x＝7为例进行示意，本申请对于x的具体取值不做限定。
在一些实施例中，如图3所示，第一参考线623和第二参考线624沿漏波天线600的长轴不对称。其中，这里的长轴可以是指漏波天线600沿第二方向的中轴线，也可以是与中轴线平行的其他轴线。例如图3中，第一参考线623和第二参考线624均为正弦曲线，二者在长轴方向上存在一定的错位(即二者在长轴方向上存在预设相位差)，从而使得二者沿长轴不对称。在一些实施例中，所述预设相位差使得漏波天线在边射角度为0°的方向上能够连续扫描。
在实际应用中，当第一参考线623和第二参考线624采用周期性设计时，漏波天线600所辐射的波束会产生边射阻带效应，即，在边射角度为0°的方向存在扫描盲区，使得波束的边射扫描范围并不连续。本申请通过对第一参考线623和第二参考线624进行不对称设计，能够消除边射阻带效应，使得波束也能够扫描到边射角度为0°方向，从而波束的边射扫描范围连续，扩大了波束的边射扫描范围。
下面结合图7和图8对采用漏波天线实现目标波束的二维扫描的扫描结果进行说明。
图7示出了根据本说明书的实施例提供的波束扫描***在yOz平面的辐射方向图，图8示出了根据本说明书的实施例提供的波束扫描***在xOy平面的辐射方向图。其中，波束扫描***包括天线模组和信号处理电路。天线模组采用3个漏波天线600在xOz平面内沿x轴方向依次排布，每个漏波天线600的延伸方向为z轴方向。每个漏波天线600的结构如图3至图6所示，并且漏波天线600的各项参数如下：
正弦曲线的周期数量x＝20；
正弦曲线的周期长度ps3＝1.76mm
缝隙的宽度ws＝0.1mm；
相邻两个缝隙的中轴线之间的距离ps2＝0.22mm；
金属化通孔的半径r＝0.25mm；
相邻两个金属化通孔的中心点之间的距离ps1＝0.44mm；以及
有效波导宽度wg＝2.1mm。
漏波天线600的工作频段为60GHz～64GHz。信号处理电路向3个漏波天线600分别提供一路电信号，并调整3路电信号的频率在上述工作频段范围内不断变化，以及调整3路电信号之间的相位差。在测试过程中，采集天线模组所辐射的目标波束的指向，得到如图7和图8所示的辐射方向图。
参见图7，在yOz平面上，当信号处理电路向漏波天线600输入的电信号的频率为60GHz时，目标波束的指向为27°(phi＝180°)；当信号处理电路向漏波天线600输入的电信号的频率为62GHz时，目标波束的指向为3°(phi＝180°)；当信号处理电路向漏波天线600输入的电信号的频率为64GHz时，目标波束的指向为31°(phi＝360°)。由此可见，随着电信号的频率在上述工作频段内不断变化，目标波束沿yOz平面的扫描范围可达58°。参见图8，在xOy平面上，信号处理电路通过调整三路电信号之间的相位差，使得目标波束沿xOy平面的扫描范围可达90°。
综上所述，本申请提供的波束扫描***，包括天线模组和信号处理电路，其中，天线模组包括在第一平面内沿第一方向排布的N个发射天线，N为大于1的整数，每个发射天线沿第一平面的第二方向延伸，并被配置为将电信号转化成毫米波电磁信号，N个发射天线发出的N个毫米波电磁信号形成目标波束；信号处理电路与天线模组连接，工作时通过为N个发射天线分别输出一路频率及相位可控的电信号，来控制目标波束进行二维扫描。由此可见，本申请方案能够在天线模组仅沿一个方向(第一方向)排布多个发射天线的情况下，通过信号处理电路调整向N个发射天线输出的电信号的频率和相位，实现目标波束的二维扫描。相比相关技术需要在多个方向均布设多个发射天线而言，减少了天线模组中的发射天线的数量，相应的，配合发射天线工作的通道的数量也会减少，从而能够降低成本。也就是说，本申请提供的波束扫描***能够在低成本的情况下，实现目标波束的二维扫描。
上述对本说明书特定实施例进行了描述。其他实施例在所附权利要求书的范围内。在一些情况下，在权利要求书中记载的动作或步骤可以按照不同于实施例中的顺序来执行并且仍然可以实现期望的结果。另外，在附图中描绘的过程不一定要求示出特定顺序 或者连续顺序才能实现期望的结果。在某些实施方式中，多任务处理和并行处理也是可以的或者是可能有利的。
综上所述，在阅读本详细公开内容之后，本领域技术人员可以明白，前述详细公开内容可以仅以示例的方式呈现，并且可以不是限制性的。尽管这里没有明确说明，本领域技术人员可以理解本说明书需求囊括对实施例的各种合理改变，改进和修改。这些改变，改进和修改旨在由本说明书提出，并且在本说明书的示例性实施例的精神和范围内。
此外，本说明书中的某些术语已被用于描述本说明书的实施例。例如，“一个实施例”，“实施例”和/或“一些实施例”意味着结合该实施例描述的特定特征，结构或特性可以包括在本说明书的至少一个实施例中。因此，可以强调并且应当理解，在本说明书的各个部分中对“实施例”或“一个实施例”或“替代实施例”的两个或更多个引用不一定都指代相同的实施例。此外，特定特征，结构或特性可以在本说明书的一个或多个实施例中适当地组合。
应当理解，在本说明书的实施例的前述描述中，为了帮助理解一个特征，出于简化本说明书的目的，本说明书将各种特征组合在单个实施例、附图或其描述中。然而，这并不是说这些特征的组合是必须的，本领域技术人员在阅读本说明书的时候完全有可能将其中一部分设备标注出来作为单独的实施例来理解。也就是说，本说明书中的实施例也可以理解为多个次级实施例的整合。而每个次级实施例的内容在于少于单个前述公开实施例的所有特征的时候也是成立的。
本文引用的每个专利，专利申请，专利申请的出版物和其他材料，例如文章，书籍，说明书，出版物，文件，物品等，可以通过引用结合于此。用于所有目的全部内容，除了与其相关的任何起诉文件历史，可能与本文件不一致或相冲突的任何相同的，或者任何可能对权利要求的最宽范围具有限制性影响的任何相同的起诉文件历史。现在或以后与本文件相关联。举例来说，如果在与任何所包含的材料相关联的术语的描述、定义和/或使用与本文档相关的术语、描述、定义和/或之间存在任何不一致或冲突时，使用本文件中的术语为准。
最后，应理解，本文公开的申请的实施方案是对本说明书的实施方案的原理的说明。其他修改后的实施例也在本说明书的范围内。因此，本说明书披露的实施例仅仅作为示例而非限制。本领域技术人员可以根据本说明书中的实施例采取替代配置来实现本说明书中的申请。因此，本说明书的实施例不限于申请中被精确地描述过的实施例。

Claims (15)

  1. 一种波束扫描***，其特征在于，包括：
    天线模组，包括在第一平面内沿第一方向排布的N个发射天线，所述N为大于1的整数，每个所述发射天线沿所述第一平面的第二方向延伸，并被配置为将电信号转化成毫米波电磁信号，所述N个发射天线发出的N个所述毫米波电磁信号形成目标波束；以及
    信号处理电路，与所述天线模组连接，工作时通过为所述N个发射天线分别输出一路频率及相位可控的所述电信号，控制所述目标波束进行二维扫描。
  2. 根据权利要求1所述的***，其特征在于，为了控制所述目标波束进行二维扫描，所述信号处理电路：
    通过调整所述N路电信号的频率在预设频段内变化，来控制所述目标波束的指向沿第二平面扫描。
  3. 根据权利要求2所述的***，其特征在于，所述第二平面与所述第一平面垂直，且与所述第二方向平行。
  4. 根据权利要求2所述的***，其特征在于，每个所述发射天线沿所述第二方向对应有K个辐射单元，每个所述辐射单元将所述电信号部分的转化为所述毫米波电磁信号，所述K为大于1的整数；
    其中，任意相邻的两个所述辐射单元发出的所述毫米波电磁信号之间具有第一相位差，且所述第一相位差随所述电信号的频率变化而变化，使得所述目标波束的指向沿所述第二平面扫描。
  5. 根据权利要求4所述的***，其特征在于，每个所述发射天线包括沿所述第二方向延伸的长轴，且在所述长轴的两侧对应有第一参考线和第二参考线，所述第一参考线和所述第二参考线分别为沿所述第二方向延伸的非直线；以及
    每个所述辐射单元的两端分别位于所述第一参考线和所述第二参考线上。
  6. 根据权利要求5所述的***，其特征在于，所述第一参考线和所述第二参考线分别为光滑曲线，使得所述发射天线工作时的能量损耗小于预设阈值。
  7. 根据权利要求5所述的***，其特征在于，所述第一参考线和所述第二参考线均为周期性的目标曲线或者目标折线。
  8. 根据权利要求5所述的***，其特征在于，所述第一参考线和所述第二参考线沿所述长轴不对称。
  9. 根据权利要求2所述的***，其特征在于，每个所述发射天线包括第一金属片，所述第一金属片上沿所述第二方向依次设置有K个缝隙；
    其中，在所述发射天线工作时，所述K个缝隙部分地泄露所述毫米波电磁信号形成所述K个辐射单元。
  10. 根据权利要求9所述的***，其特征在于，每个所述缝隙的边缘为光滑边缘。
  11. 根据权利要求9所述的***，其特征在于，每个所述发射天线还包括：
    基板，包括相背设置的第一面和第二面，所述第一金属片设置在所述第一面上；
    第二金属片，设置在所述第二面上，被配置为接地；以及
    多个金属化通孔，每个所述金属化通孔均贯通所述第一金属片、所述基板和所述第二金属片，且所述多个金属化通孔包围所述K个缝隙。
  12. 根据权利要求1所述的***，其特征在于，为了控制所述目标波束进行二维扫描，所述信号处理电路：
    通过调整所述N路电信号之间的第二相位差，来控制所述目标波束的指向沿第三平面扫描。
  13. 根据权利要求12所述的***，其特征在于，所述第三平面与所述第一平面垂直，且与所述第一方向平行。
  14. 根据权利要求1所述的***，其特征在于，所述天线模组的工作波长为λ，所述天线模组中任意两个相邻的所述发射天线之间的距离为d1，所述d1与λ/2之间的差值在预设范围内。
  15. 根据权利要求1所述的***，其特征在于，所述天线模组的工作频段包括：60GHz-64GHz。
PCT/CN2022/131135 2022-11-10 2022-11-10 波束扫描*** WO2024098326A1 (zh)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090066597A1 (en) * 2007-09-07 2009-03-12 Songnan Yang Substrate Integrated Waveguide Antenna Array
CN105720376A (zh) * 2016-02-15 2016-06-29 北京交通大学 漏波天线及基于漏波天线的波束赋形方法
US20180309197A1 (en) * 2015-11-12 2018-10-25 Duke University Printed cavities for computational microwave imaging and methods of use
CN109980363A (zh) * 2017-12-28 2019-07-05 华为技术有限公司 基于基片集成波导的阵列天线
CN111463578A (zh) * 2020-03-30 2020-07-28 深圳市信维通信股份有限公司 一种基片集成波导漏波天线
CN112436268A (zh) * 2020-11-06 2021-03-02 华东师范大学 一种双波束的频率扫描漏波天线
CN113410659A (zh) * 2021-06-20 2021-09-17 复旦大学 一种宽角扫描的基片集成波导缝隙天线阵
CN114447631A (zh) * 2022-01-14 2022-05-06 深圳市道通智能汽车有限公司 一种发射天线阵列、发射天线***及毫米波雷达

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090066597A1 (en) * 2007-09-07 2009-03-12 Songnan Yang Substrate Integrated Waveguide Antenna Array
US20180309197A1 (en) * 2015-11-12 2018-10-25 Duke University Printed cavities for computational microwave imaging and methods of use
CN105720376A (zh) * 2016-02-15 2016-06-29 北京交通大学 漏波天线及基于漏波天线的波束赋形方法
CN109980363A (zh) * 2017-12-28 2019-07-05 华为技术有限公司 基于基片集成波导的阵列天线
CN111463578A (zh) * 2020-03-30 2020-07-28 深圳市信维通信股份有限公司 一种基片集成波导漏波天线
CN112436268A (zh) * 2020-11-06 2021-03-02 华东师范大学 一种双波束的频率扫描漏波天线
CN113410659A (zh) * 2021-06-20 2021-09-17 复旦大学 一种宽角扫描的基片集成波导缝隙天线阵
CN114447631A (zh) * 2022-01-14 2022-05-06 深圳市道通智能汽车有限公司 一种发射天线阵列、发射天线***及毫米波雷达

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